Anti-bacterial dolphins?

Scientists find anti-bacterial chemicals are building up in dolphins.

Anti-bacterial products have become enormously popular over the past several years as consumers see them as a way to ward off potentially harmful colds and other illnesses. Without thinking about it, many Americans immerse themselves in anti-bacterial hand soap, toothpaste, and deodorant in an effort to get clean. But it turns out our infatuation with clean may be harmful to our own health and that of the planet.

Triclosan is the anti-bacterial agent of choice found in many consumer products, including liquid hand soaps, toothpaste and deodorants. And scientists have recently found that dolphins, and other aquatic species are literally swimming in the stuff — it is accumulating at concentrations known to disrupt the hormones and growth and development of other animals.

One-third of the bottlenose dolphins tested off South Carolina and almost one-quarter of those tested off Florida carried traces of triclosan in their blood. It is the first time the chemical has been reported in a wild marine mammal — a finding that many scientists and health experts find worrisome because it shows that triclosan is building up in the ocean’s food web.

“The fact that this chemical is found in the environment and is being detected in a top level predator certainly warrants concern,” said Patricia Fair, a research physiologist at the National Oceanic and Atmospheric Administration and lead author of the dolphin study, which was published online in the journal Environmental Pollution in May.

No studies have been done yet to evaluate what effect triclosan might have on dolphins, but research on other animals suggests that it is likely harmful to their health. Studies in bullfrogs and rats found that triclosan disrupts the endocrine system — blocking the animals' thyrod and endocrine development at concentrations currently found in the dolphins' environment.

Caren Helbing, a molecular biologist at the University of Victoria in British Columbia and author of the bullfrog study, explained that triclosan is strikingly similar to thyroid hormones, so it might bind to hormone receptors. Because frog and mammal endocrine systems are similar, triclosan can potentially “affect how hormones work in ways that aren’t intended” in dolphins, and maybe even humans, she said.